1. FIELD OF THE INVENTION
The present invention relates to automated machine equipment and in particular automated machine equipment utilizing a tool slide system which will accommodate a plurality of tool holders. One such common machine will be known to those skilled in the art as an automatic screw machine or as a multiple spindle bar machine.
2. DESCRIPTION OF THE PRIOR ART
As will be familiar to those skilled in the art, machine equipment, such as an automatic screw machine, will often have a stock spindle assembly which will comprise a spindle carrier and a number of spindles, each of which will accommodate a length of bar stock. This spindle assembly may contain a number of spindles and it is not uncommon to see a spindle assembly having six or eight spindles positioned around the circumference thereof. Each of the spindles will retain the bar stock during machining operations and will automatically feed the required length of stock for the operation to be accomplished. Generally, an end tool carrier will be positioned on a center line with the spindle assembly and will provide a number of positions for tool holder assemblies. Depending upon the operations to be performed on the stock, one or more tools will be secured to the end tool slide carrier which is arranged to move into the work piece and perform the necessary machining operation and then move away from the work piece to permit rotation of the spindle assembly. As will be understood by those skilled in the art, such an automatic machining apparatus may include cross slides which are arranged perpendicular to the axis through the spindle assembly and the end tool slide carrier. The cross slides, like the end tool slide carriers, are arranged to address the bar stock and perform additional machining operations.
In the prior art, automatic machine screws have utilized mechanical cam means for controlling the address and withdraw of the end tool slide carrier as well as the cross slides. One such prior art apparatus is known as an Acme-Gridley.RTM. multiple spindle bar machine which is available from National Acme, 170 East 131st Street, Cleveland, Ohio 44108. In such a prior art device, the position stock feed, the cross slides and the end tool carrier were controlled through the use of a drum or barrel cam arrangement and a slide roll or cam follower. If a change was desired in any of the mechanical operations of the device, such change was effected by changing the drum cams and/or assembling a plurality of cam parts on the drum to arrive at the desired drum cam configuration. Such a prior art device is illustrated in FIG. 5. Those skilled in the art will be familiar with the technique of changing the drum cam and/or assembling cam sections to a host drum for the purpose of providing a new or different drum cam.
More recently, bar machines have been introduced which utilize cross slides which eliminate the need for barrel or drum cams in the cross slide position through the use of programmable controls and servo mechanisms. One such apparatus is available from National Acme as a 11/4 RA-6 Spindle Servo Slide Bar Machine. However, those skilled in the art will recognize that such a machine still requires that the end tool slide carrier assembly be controlled through the use of the mechanical drum cam and follower mechanisms.
With reference again to FIG. 5, there is shown such a drum cam 500 and follower mechanism 508 from the prior art machines. In such an assembly, the cam portions 501-506 must be changed in order to modify or alter the address and withdraw of the end tool slide carrier assembly. Such modifications are time consuming and require precision assembly of the tool slide cams. In such a prior art construction, a plurality of cam portions are utilized to create a cam track 507 on the barrel or drum 140. The cam follower 508 is then positioned within the cam track and will mechanically move the end tool slide carrier assembly 100 through its address to the work, provide feed where the work is performed on the stock and will then withdrawal the end tool carrier assembly. In addition to modifications to the tool slide cams, it is necessary to adjust a stop rod, not shown, which is positioned on the guide bracket which supports the tool slide during its movement. The stop rod provides positive adjustment for maximum travel by eliminating variations in machine tolerances caused by cam and roller clearances. Such a positive stop is necessary to assure sustaining machine accuracy and repeatability in view of cam wear and cam follower clearances.
Although the prior art devices have proven reliable for mass production of large quantities of the desired article, the complex and time consuming procedure which is required to change the end tool slide movement has resulted in substantial machine set-up cost and adjustment time. In addition to the time spent in setting up the equipment, the substantial cost of such a set-up has limited the utility of such machinery for producing small quantities of the desired article.
In accordance with the prior art difficulties associated with machine set-up and operation, the art has desired a means of rapidly modifying and controlling tool slide systems in general and the end tool slide system in particular.